The Rings of Power Scrapped Scene Became a LotR Easter Egg
There is no doubt that The Lord of the Rings: The Rings of Power owes a lot to Peter Jackson's LotR trilogy, and that includes even smaller details, like sound design.
Remember how in the film trilogy words in the Black Speech, hissed in the background, sometimes serve as an audio cue about Sauron's will working through the One Ring, most notably at the Council of Elrond? Sound designers of the Rings of Power added an homage to Jackson's films and an Easter egg for them, by similarly including whispers in a fictional language as a motif for all magical elements of the show. But this time they do not sound malevolently, because they are not supposed to indicate malevolence in action.
The whole motif started with a single phrase, an incantation in the Elvish language, which the Stranger was supposed to utter in a scene that actually didn't make the cut. But the sound designers so liked the incantation, that they decided to weave it as whispers into sounds indicating use of magic throughout the show:
"That whisper element in the sound design came from the idea that all magic comes from Ilúvatar, the creator in Middle-earth and in the universe of Tolkien. If you look into the lore, you read into the depths of a website like the tolkiengateway.net, which is what I used — I had that tab open on my computer for two and a half years, and I was always mining that for a bit more information about what we were saying — but if you look into Ilúvatar and look at how Middle-earth was created, it was all created from his thoughts.
And so, the natural extension of that would be, "What is the sound of Ilúvatar's thoughts?" It's the magical mystical whispers. And so we worked closely with the dialect coach to pick that right phrase to use and then extend out how we used it and the different ways we recorded it and processed it. There are layers of it and it changes and develops depending on what's happening with the magic, and whether it's mysterious or whether it's dangerous," said the supervising sound editor Damian Del Borrello in an interview with /Film, which revealed many other details of his work.
Well, given that Sauron's magic is supposed to be a corrupted version of his former angelic abilities, this choice of sound effects is a good fit for Tolkien's legendarium as well, in addition to being a nod to Jackson and his sound designers.